More particularly, the object of the invention is a device for packaging and dispensing a product, comprising a container for containing the product to be dispensed by means of a dispensing accessory fitted to the container and comprising a tip.
There are known packaging devices of conventional structure for storing and dispensing a product in measured doses or drops or in any other form, while maintaining its cleanliness and sterility for the entire period of its use.
These devices are used in the pharmaceutical, cosmetic, and food industries, and some are specifically intended for the field of ophthalmology.
Such known devices are described in patents FR 2 770 495, FR 2 638 428, and FR 2 661 401, in which a container is equipped with a dispensing tip having a bacteriological filtering membrane which sterilizes the product as the product leaves the container.
In these devices, the container comprises a flexible portion which, when manually compressed, causes the product to pass through the bacteriological membrane and exit said container through the tip.
Another type of device which obtains an analogous result is described in patent EP 08 61 128, in which the product is dispensed by means of a pump fitted with a nozzle, and the pump has a bacteriological filter in the air replacement circuit.
Another type of device which obtains an analogous result is described in patents FR 04 08 031 and FR 05 10 907, in which the product is discharged through a flexible nozzle fitted to the container and acting as an accessory. This nozzle opens under the effect of the pressure created by pressure on the walls of the container holding the product or on the nozzle itself, and then closes due to its elasticity. A bacteriological filter is placed at the bottom of the container, where there is an opening for air replacement.
Other devices obtaining a similar result include a pump for dispensing the product, equipped with a nozzle and assembled onto a fluid-tight container not having an air replacement circuit.
All of these devices having a bacteriological filter either for the sterile filtration of the product itself or the sterile filtration of the replacement air, or having no filter or air replacement circuit in the container, make it possible to store the product inside the container in a clean or sterile manner for the duration of its use, and from this point of view can be considered to be effective.
However, the major disadvantage of these devices is that they do not ensure there are no bacteria on the outside of the container, particularly at the tip of the nozzle.
When a measured drop of product has been released by one of the means used in these devices, a fraction of this measured drop, which will be referred to below as the residual drop, remains at the tip of the nozzle.
Experience has shown that, for any device and method used to release a measured drop of product, it is not possible to avoid the formation of a residual drop which remains at the tip of the nozzle until the next use of the device.
The formation and subsequent presence of this residual drop is a major disadvantage because, unlike the product inside the container which can be kept clean or sterile, this residual drop remains in contact with the outside air where it could become contaminated.
The goal of these existing devices, which is to keep clean or sterile the product they contain or distribute, without the use of preservatives, is not achieved because although the product is kept clean or sterile inside the container, it can become contaminated at the tip of the distributor nozzle.
Various solutions have been proposed for solving this problem affecting all existing devices.
In the device described in patent FR 2 770 495 mentioned above, the residual drop is sucked back into the container by the effect of the suction caused by expelling the measured drop, and the recovered drop is sterilized by a sterilizing filter placed in the product dispensing circuit.
This solution is intended to eliminate the residual drop, but is not perfect because the suction created inside the container after the measured drop is expelled is not always sufficient to overcome the resistance of the sterilizing filter to the passage of this residual drop, and the drop therefore may not be sucked back into the container.
Another solution has been proposed for devices such as those described in patent EP 08 61 128. This solution consists of having a metal insert with bactericidal properties, such as silver, placed inside the nozzle where it kills any bacteria contaminating the residual drop.
A similar solution consists of incorporating bactericidal material into the plastic which comes into contact with the residual drop.
Such devices also may allow the residual drop to dry in order to decrease the risk of bacterial contamination.
These solutions are not satisfactory, because their effectiveness is only relative and because there is a risk of metal molecules being released into the product, although these devices were designed to avoid the use of preservatives.